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Cited by 180Fish biology, ecology, and behaviorFish Ecology and Management StudiesFreshwater macroinvertebrate diversity and ecology

Effects of deforestation on fish community structure in Ecuadorian Amazon streams

Open access
Bojsen, B. H., Barriga, R.·2002·Freshwater Biology
DOI 10.1046/j.1365-2427.2002.00956.x
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Abstract

SUMMARY 1. There is little information on the impacts of deforestation on the fish fauna in neotropical streams, and on parameters influencing species diversity and community structure of fish. We analysed these aspects in 12 stream sites in the Ecuadorian Amazon. The stream sites represented a large gradient in canopy cover and were located in an area of fragmented forest. While some streams had been deforested, they had not suffered gross degradation of the habitat. 2. The species richness of stream fish was not related to deforestation. Local fish diversity (Fisher's Alpha) was positively related to the surface area of stream pools (m 2). Beta diversity was higher among forested than deforested sites, indicating greater heterogeneity in species composition among forested than deforested sites. The percentage of rare species was positively correlated with canopy cover. 3. Total fish density increased with deforestation, and the fish community changed from dominance by omnivorous and insectivorous Characiformes at forested sites to dominance of periphyton‐feeding loricariids at deforested sites. 4. Multidimensional statistical analysis of fish community structure showed that six environmental variables (the area of stream bottom covered by leaves, relative pool area, particulate organic matter, mean depth, conductivity and suspended solids) were related to the ordination axes. The presence of leaves, which was strongly correlated to canopy cover, was the variable most closely related to fish community structure, while relative pool area was the second strongest variable. Thus, fish community structure was strongly affected by deforestation.

AI snapshot

Written from the paper’s full text.

TL;DR

In 12 Ecuadorian Amazon stream sites spanning a canopy-cover gradient, deforestation did not reduce fish species richness but increased total fish density and shifted biomass dominance toward periphyton-feeding loricariids. Fish community structure was most strongly related to leaf cover on the stream bottom, followed by relative pool area.

Key findings

  • Species richness was not related to deforestation: 42 species were caught in deforested sites versus 35 in forested sites, with mean species richness 20 versus 15 and mean Fisher’s Alpha 3.34 versus 2.92, neither significantly different.
  • Beta diversity was higher among forested than deforested sites (Whittaker’s Beta 1.31 versus 1.12; Routledge’s Beta 0.52 versus 0.22), and the percentage of rare species was positively correlated with canopy cover (r = 0.62*).
  • Total fish density increased with deforestation, while total biomass was not significantly related to canopy cover (P = 0.08); Loricariidae made up 29% of biomass in deforested sites versus 5% in forested sites.
  • Correspondence analysis linked fish community structure most strongly to leaf cover on the stream bottom (axis 1 correlation 0.90*), with relative pool area, mean depth, conductivity, and suspended solids also related to axis 2.

Methods

  • The study sampled 12 sites in nine headwater streams (orders 1–3) in the upper Rio Napo catchment, Ecuadorian Amazon; six sites were forested (canopy cover >50%) and six deforested (canopy cover <50%), with canopy cover ranging from 6 to 82%.
  • Fish were sampled in 1999 during wet and dry seasons using push seine, gill net, and minnow traps; density and biomass estimates included active and gill-net fishing, while trap catches were excluded from quantitative estimates and used only for species richness.
  • Analyses included Fisher’s Alpha diversity, beta diversity indices, PCA on 27 environmental variables, DCA/CA ordination of fish assemblage data, and Spearman/Pearson correlations with habitat variables.

Limitations

  • The paper states that fish abundance data are semiquantitative because none of the sampling techniques used are truly quantitative, and trap catches were excluded from density and biomass estimates.
  • The authors note that distinguishing stream-size effects from deforestation effects is difficult, and that their study area involved small-scale forest fragmentation rather than clear cutting with gross habitat degradation.
  • The paper states it did not demonstrate increased periphyton productivity with declining canopy cover, only higher periphyton biomass and likely light availability; evident limitations include the small sample of six sites per category and the correlational, single-timeframe design.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1046/j.1365-2427.2002.00956.x

Cites

36 of 36 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 39 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Species richness of stream fish was not related to deforestation in the studied Ecuadorian Amazon streams.

    “The species richness of stream fish was not related to deforestation.”
    Quote in the paperSubstantial claim
  • Findingown data

    DCA of the fish species data resulted in an axis 1 gradient length of 3.4 SD.

    “Ordination by DCA for the fish species data resulted in an axis 1 gradient length of 3.4 SD, indicating that species turnover was at a range where non-linear methods are appropriate (results not shown) (ter Braak & Prentice, 1988).”
    Quote in the paperSubstantial claim
  • Findingown data

    Six environmental variables (area of stream bottom covered by leaves, relative pool area, particulate organic matter, mean depth, conductivity and suspended solids) were related to the ordination axes of fish community structure.

    “Multidimensional statistical analysis of fish community structure showed that six environmental variables (the area of stream bottom covered by leaves, relative pool area, particulate organic matter, mean depth, conductivity and suspended solids) were related to the ordination axes.”
    Quote in the paperSubstantial claim
  • Findingown data

    Of the total number of species in forested and deforested sites, Siluriformes accounted for 20% and 26%, respectively.

    “Of the total number of species in the forested and deforested sites, Characiformes accounted for 44 and 50%, and Siluriformes for 20 and 26%, respectively.”
    Quote in the paperNot a substantial claim
  • Findingown data

    A total of 2405 individuals, representing 48 species and 16 families, were collected in the 12 stream reaches.

    “A total of 2405 individuals, representing 48 species and 16 families, were collected in the 12 stream reaches (Table 2).”
    Quote in the paperNot a substantial claim
  • May combine two claims. 26
  • Classified as probably not a substantial claim. 28

  • May combine two claims.

    Findingown data

    Of Characidae, all 15 species occurred in deforested sites but only 11 in forested sites.

    “Of Characidae, all 15 species occurred in deforested sites but only 11 in forested sites.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In some deforested sites, loricariid species made up more than 50% of the total biomass, while the relative abundance of omnivorous and insectivorous Characiformes declined.

    “In some deforested sites the loricariid species made up more than 50% of the total biomass, while the relative abundance of omnivorous and insectivorous Characiformes declined.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Leaf cover was closely correlated with canopy cover and reflected the degree of deforestation.

    “Leaf cover was closely correlated with canopy cover (Table 1) and reflected the degree of deforestation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Patterns in fish species diversity, overall density and biomass, and community structure were mainly related to leaf cover on the stream bottom, canopy cover at the stream reach scale, and to absolute and relative pool areas.

    “Patterns in fish species diversity, overall density and biomass, and community structure were mainly related to leaf cover on the stream bottom, canopy cover at the stream reach scale, and to absolute and relative pool areas.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    One site with low canopy cover had high leaf cover and high conductivity.

    “Also, one site with low canopy cover had high leaf cover and high conductivity.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The lower heterogeneity of the fish fauna in deforested sites was not due to a decline in the absolute number of rare species, but rather to a greater abundance of certain species in deforested sites.

    “The lower heterogeneity of the fish fauna in the deforested sites was not due to a decline in the absolute number of rare species, but rather to a greater abundance of certain species in the deforested sites.”
    • Also stated in: § Species diversity · plain
      “In other words, some species changed from being rare in the forested sites to being common in the deforested sites.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In deforested sites, beta diversity (species heterogeneity) and the relative presence of rare species were lower than in forested sites.

    “In the deforested sites, Beta diversity (i.e.species heterogeneity) and the relative presence of rare species was lower than in forested sites.”
    • Also stated in: § Do periphyton-feeders dominate as a result of deforestation? · plain
      “Deforestation influenced the fish fauna by leading to (1) a lower heterogeneity in species composition between sites”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The forested site with low leaf cover had the lowest canopy cover (68%) among forested sites and was shallow with high current velocity.

    “This forested site had the lowest canopy cover (68%) among the forested sites and was shallow with high current velocity.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    One site with high canopy cover had low leaf cover.

    “However, one site with high canopy cover had low leaf cover.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    Total fish density and biomass were positively affected by deforestation, while species richness was unaffected.

    “Our results showed, however, that total fish density and biomass were positively affected by deforestation, while species richness was unaffected.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    Pool size is important for species richness, species composition and abundance.

    “Our study emphasises the importance of pool size for species richness, species composition and abundance”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Total fish biomass was positively related to relative pool area, but not to absolute pool area.

    “Although total fish biomass was positively related to relative pool area, but not to absolute pool area, we assume that this relationship reflects space limitation.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    For temperate streams, riparian canopy cover is a very important parameter structuring the fish fauna in relation to longitudinal distribution and to deforestation.

    “For temperate streams, riparian canopy cover is a very important parameter structuring the fish fauna in relation to longitudinal distribution and to deforestation (e.g.Schlosser, 1991;Hughes & Noss, 1992;Lenat & Crawford, 1994;Collares-Pereira et al., 1995;Wang et al., 1997;Harding et al., 1998;Jones et al., 1999;Marsh-Matthews & Matthews, 2000).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Schlosser, 1991 source
    • cites Hughes & Noss, 1992 source
    • cites Lenat & Crawford, 1994 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In Mexico, Lyons et al. (1995) found more individuals in deforested streams.

    “in Mexico, Lyons et al. (1995) found more individuals in deforested streams.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lyons et al., 1995 source

  • Classified as probably not a substantial claim.

    Premisecitation

    In Costa Rica, Burcham (1988) found species richness in pasture streams to be higher than in forest streams.

    “In Costa Rica, Burcham (1988) found species richness in pasture streams to be higher than in forest streams.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Burcham, 1988

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Premisenone given

    Most studies have been conducted in areas affected by clear cutting, leading to a profound degradation of stream habitats.

    “In addition, most studies have been conducted in areas affected by clear cutting, leading to a profound degradation of stream habitats.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductown data

    Half of the 12 study sites were forested (canopy cover >50%) and half were deforested (canopy cover <50%), resulting in a canopy cover gradient from 6 to 82%.

    “Half of the sites were forested (undisturbed by clear cutting at the study site; canopy cover >50%) while the other half were deforested (disturbed by clear cutting at the study site; canopy cover <50%), resulting in a gradient of canopy cover from 6 to 82% among the 12 study sites.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    Conclusions in stream studies are often confounded by differences in physical characteristics.

    “Conclusions are often confounded by differences in physical characteristics.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductnone given

    The stream sites represented a large gradient in canopy cover and were located in an area of fragmented forest.

    “The stream sites represented a large gradient in canopy cover and were located in an area of fragmented forest.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    A basic difficulty in stream studies is to distinguish between the effects of stream size (longitudinal effects) and the effects of deforestation.

    “A basic difficulty in stream studies is to distinguish between the effects of stream size (longitudinal effects) and that of deforestation.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisenone given

    Little information exists concerning the impact of deforestation on fish assemblages in streams, or on the processes structuring fish communities in tropical streams.

    “Despite the extensive ongoing deforestation in tropical areas little information exists concerning its impact on fish assemblages in streams, or even on the processes structuring fish communities in tropical streams.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The opposite conclusion (higher species richness in forest streams) was reached for Mexican and African streams.

    “The opposite conclusion was reached for Mexican (Lyons et al., 1995) and African streams (Kamdem Toham & Teugels, 1999).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Lyons et al., 1995 source
    • cites Kamdem Toham & Teugels, 1999 source

  • Probably not a substantial claim: may not pass S1 (asserted).

    Premisecitation

    Some authors have proposed that a greater proportion of the fish community is supported by autochthonous sources of food in deforested catchments.

    “Some authors have proposed that a greater proportion of the fish community is supported by autochthonous sources of food in deforested catchments (Angermeier & Karr, 1983;Burcham, 1988).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Angermeier & Karr, 1983 source
    • cites Burcham, 1988

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    Research on fish community structure, species richness and density in temperate and tropical regions shows equivocal results on the effects of deforestation.

    “Research on fish community structure, species richness and density in temperate and tropical regions shows equivocal results on the effects of deforestation.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Burcham, 1988

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Lyons et al., 1995 source
    • cites Kamdem Toham & Teugels, 1999 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Some studies on the longitudinal succession of tropical stream fish and on the relationship between the tropical riverine environment and the fish fauna have suggested an impact of deforestation.

    “Some studies on the longitudinal succession of tropical stream fish, and on the relationship between the tropical riverine environment and the fish fauna, have suggested an impact of deforestation (e.g.Angermeier & Karr, 1983;Castro & Casatti, 1997;Kamdem Toham & Teugels, 1998)”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Angermeier & Karr, 1983 source
    • cites Castro & Casatti, 1997

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Kamdem Toham & Teugels, 1998 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In Africa, Kamdem Toham & Teugels (1999) found fewer individuals per sample in deforested streams.

    “In Africa, Kamdem Toham & Teugels (1999) found fewer individuals per sample in deforested streams”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Kamdem Toham & Teugels, 1999 source

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    The study was conducted in an area of fragmented forest with streams that had not suffered dramatic changes in habitat characteristics.

    “The study was conduc-ted in an area of fragmented forest with streams that had not suffered dramatic changes in habitat characteristics.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Power (1984) found a significant increase in the density of periphyton-feeding catfishes (Loricariidae) in Panamanian streams with decreasing canopy cover.

    “Power (1984) also found a significant increase in the density of the periphyton-feeding catfishes (Loricariidae) in Panamanian streams with decreasing canopy cover.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Power, 1984 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Jones et al. (1999) found that total fish abundance decreased with deforestation upstream of their sampling sites in the little Tennessee River drainage in North Carolina and Georgia.

    “In contrast, Jones et al. (1999) found that total fish abundance decreased with deforestation upstream of their sampling sites in the little Tennessee River drainage in North Carolina and Georgia”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Jones et al. (1999) source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Current velocity, water depth and substratum type have been related to stream fish community patterns in many studies.

    “These parameters have been related to stream fish community patterns in many studies (Pusey, Arthington & Read, 1993;Taylor, Winston & Matthews, 1993;Kamdem Toham & Teugels, 1998)”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Pusey, Arthington & Read, 1993 source
    • cites Taylor, Winston & Matthews, 1993 source
    • cites Kamdem Toham & Teugels, 1998 source

  • May combine two claims.

    Interpretationnone given

    Species positioned at the centre of the CA diagram are unrelated to the ordination axes and are ubiquitous.

    “Those species positioned at the centre of the diagram are unrelated to the ordinations axis, and are ubiquitous species”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The seven species that increased in occurrence are either omnivorous or insectivorous and probably became more abundant because of the increase in macroinvertebrate density at the deforested sites.

    “These species are either omnivorous or insectivorous and probably became more abundance because of the increase in macroinvertebrate density at the deforested sites.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Jones et al. (1999) found the abundance of fine sediment to increase with the length of deforested reaches upstream of the sampling sites.

    “and Jones et al. (1999) found the abundance of fine sediment to increase with the length of deforested reaches upstream of the sampling sites.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Jones et al. (1999) source

  • May combine two claims.

    Interpretationreasoning

    Density might not reflect the use of space as well as biomass, which could explain why total density was not related to relative pool area.

    “Density might therefore not reflect the use of space as well as biomass, and this could explain why total density was not related to relative pool area.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The positive relationship between total fish biomass and relative pool area reflects space limitation.
    • Rests on an assumption: There are large differences in the body size of tropical stream fish and small individuals often dominate the fauna.

  • May combine two claims.

    Interpretationreasoning

    Leaf cover might have been a better predictor of fish community structure than canopy cover, because other parameters such as current velocity, water depth and substratum type also influenced the retention of leaves on the stream bottom.

    “Leaf cover might have been a better predictor of fish community structure than canopy cover, because other parameters such as current velocity, water depth and substratum type also influenced the retention of leaves on the stream bottom.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Periphyton biomass was important not only for community structure overall, but also for the size structure of periphyton-feeding fish.

    “suggesting that periphyton biomass was not only important for community structure overall, but also for the size structure of periphyton-feeding fish.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Previous studies have demonstrated a positive effect of deforestation on total fish abundance.

    “Previous studies have demonstrated a positive effect of deforestation on total fish abundance (Lenat & Crawford, 1994;Agostinho & Penczak, 1995;Lyons et al., 1995;Harding et al., 1998).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Lenat & Crawford, 1994 source
    • cites Agostinho & Penczak, 1995 source
    • cites Lyons et al., 1995 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    These parameters may also have influenced our results.

    “and they may also have influenced our results.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Loricariids may be less at risk of predation by birds and mammals when in pools.

    “Also, fish such as loricariids may be less at risk of predation by birds and mammals when in pools (Power, 1984).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Power, 1984 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Many species are associated with large pools.

    “Many species are associated with large pools (Angermeier & Karr, 1983).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Angermeier & Karr, 1983 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    This relationship might depend on the size of the pools.

    “This relationship might depend on the size of the pools.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Relative pool area is correlated with pool morphology, and may reflect the influence of current velocity, substratum type and food availability.

    “This parameter is correlated with pool morphology, and may reflect the influence of current velocity, substratum type and food availability.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Pools are a heterogeneous habitat, with low current velocity and often rich in allochthonous food resources, which are favoured by many fish species.

  • May combine two claims.

    Interpretationreasoning

    The positive effects on density and biomass and the lack of effect on species richness may depend on stream habitat quality not being substantially affected by deforestation at our sites, while density and biomass benefited from larger food availability in deforested sites.

    “These results may depend on the fact that stream habitat quality was not substantially affected by deforestation at our sites, while fish density and biomass appeared to benefit from the larger amount of food (periphyton and macroinvertebrates) available in the deforested sites.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The positive relationship between species richness and habitat size is not only associated with sampling effort, but is also due to increasing habitat heterogeneity.

    “The positive relationship between species richness and habitat size is not only associated with sampling effort, but is also due to increasing habitat heterogeneity, as suggested by Williams (1964).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Williams (1964)

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    Species positioned at the edge of the CA diagram are rare species.

    “The species positioned at the edge of the diagram are rare species.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Burcham (1988) found that periphyton-feeding fish dominated a Costa Rican stream surrounded by pasture while they made up only a small proportion of the fish fauna in a forested stream.

    “Burcham (1988) found that periphyton-feeding fish dominated a Costa Rican stream surrounded by pasture while they made up only a small proportion of the fish fauna in a forested stream.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Burcham (1988)

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Fish faunas in neotropical streams are often dominated by benthic species.

    “Fish faunas in neotropical streams are often dominated by benthic species (Covich, 1988)”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Covich, 1988 source

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Burcham's forested stream had a clay/silt substratum, and the pasture stream had a cobble/gravel substratum.

    “Because the forested stream had a clay ⁄ silt substratum, and the pasture stream had a cobble ⁄ gravel substratum”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Burcham (1988)

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    Siltation likely has a strong negative impact.

    “and it is likely that siltation has a strong negative impact.”
    Quote in the paperNot a substantial claim
49 of 49

  • The paper relies on this without support.

    Periphyton-feeding fish are common in Neotropical streams.

    “Because periphyton-feeding fish are common in Neotropical streams, we hypothesised that the increased dominance of periphyton-feeding fishes would be a consequence of deforestation.”

  • The paper relies on this without support.

    Little information is available on the influence of small-scale deforestation (fragmentation of forest by subsistence farmers) on stream fish communities in the Amazon and elsewhere.

    “Little information is available on the influence of small-scale deforestation (fragmentation of forest by subsistence farmers) on stream fish communities in the Amazon and elsewhere.”

  • The paper relies on this without support.

    The deforested streams had not suffered gross degradation of the habitat.

    “While some streams had been deforested, they had not suffered gross degradation of the habitat.”

  • The paper relies on this without support.

    It is possible to identify four major pool habitats (edge, bottom, surface and middle), while riffles have only the bottom and edge habitat.

    “It is possible to identify four major pool habitats (edge, bottom, surface and middle), while riffles have only the bottom and edge habitat.”

  • The authors state this as an assumption.

    The positive relationship between total fish biomass and relative pool area reflects space limitation.

    “Although total fish biomass was positively related to relative pool area, but not to absolute pool area, we assume that this relationship reflects space limitation.”

  • The paper relies on this without support.

    There are large differences in the body size of tropical stream fish and small individuals often dominate the fauna.

    “There are large differences in the body size of tropical stream fish and small individuals often dominate the fauna.”

  • The paper relies on this without support.

    Several fish species use fallen leaves for feeding and shelter.

    “Finally, several species use fallen leaves for feeding and shelter, making them an important structural and functional parameter.”

  • The paper relies on this without support.

    Opposing patterns (positive and negative effects of deforestation) have been found for species richness.

    “The same opposing patterns were found for species richness.”

  • The paper relies on this without support.

    Pools are a heterogeneous habitat, with low current velocity and often rich in allochthonous food resources, which are favoured by many fish species.

    “As already discussed, pools are a heterogeneous habitat, with low current velocity and often rich in allochthonous food resources, which are favoured by many fish species.”
9 of 9

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Methods and results specify different areas for the Fisher's Alpha residual regression

    Major

    The methods say Fisher's Alpha was regressed against total stream reach area to obtain the residuals. The results say the residuals came from a regression against pool area.

  • Current-velocity calculation reverses the units of velocity

    Minor

    Dividing elapsed time by reach length gives time per distance, whereas the reported velocity unit is distance per time.

  • Reported mean pebble cover exceeds its stated range

    Minor

    Appendix 1 reports mean pebble cover of 22% for deforested sites, but gives a range whose maximum is 20%. A mean cannot exceed every value in its range.

  • Figure 5 regression rises with canopy cover despite the stated inverse relationship

    Minor

    The reported regression has a positive slope, so it predicts increasing log-transformed loricariid biomass percentage as canopy cover increases. The results state that relative loricariid biomass is inversely related to canopy cover.

4 of 4

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Castro R.M.C., 1997, The fish fauna from a small forest stream of the upper Paraná River basin, southeastern Brazil, Ichthyological Exploration of Freshwaters, 7, 337

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Authors
Bojsen, B. H., & Barriga, R.
Affiliations
  • University of Copenhagen (DK)
  • National Polytechnic School (EC)
Corresponding author
Bojsen, B. H.
ORCID
Barriga, R.
Venue
Freshwater Biology
Publisher
Wiley
Published
2002-10-25
Volume
47
Issue
11
Pages
2246-2260
ISSN
  • 0046-5070 (ISSN-L)
  • 1365-2427
DOI
10.1046/j.1365-2427.2002.00956.x
OpenAlex
W2109533734
Cited by
180
References
35
Citations by year
2026: 2 · 2025: 10 · 2024: 7 · 2023: 7 · 2022: 13 · 2021: 16 · 2020: 10 · 2019: 11 · 2018: 13 · 2017: 13 · 2016: 9 · 2015: 13 · 2014: 5 · 2013: 8 · 2012: 5
FWCI
1.56
Type
journal article
Language
en
Open access
Licence
onlinelibrary.wiley.com/termsAndConditions#vor (vor)
Locations
  • Freshwater Biology (publishedVersion)
  • Research at the University of Copenhagen (University of Copenhagen) (submittedVersion)
Funders
  • Udenrigsministeriet
  • Rådet for Udviklingsforskning
  • Danish International Development Agency
Topics
  • Physical Sciences › Environmental Science › Nature and Landscape Conservation › Fish biology, ecology, and behavior
  • Physical Sciences › Environmental Science › Nature and Landscape Conservation › Fish Ecology and Management Studies
  • Physical Sciences › Environmental Science › Ecology › Freshwater macroinvertebrate diversity and ecology
Keywords
deforestation, fish community structure, Amazonian streams, canopy cover, beta diversity, species richness, fish density, Characiformes, Loricariidae, leaf cover, stream pools, habitat heterogeneity, forest fragmentation, Neotropical streams

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